Add the ShadowCallStack pass

Summary:
The ShadowCallStack pass instruments functions marked with the
shadowcallstack attribute. The instrumented prolog saves the return
address to [gs:offset] where offset is stored and updated in [gs:0].
The instrumented epilog loads/updates the return address from [gs:0]
and checks that it matches the return address on the stack before
returning.

Reviewers: pcc, vitalybuka

Reviewed By: pcc

Subscribers: cryptoad, eugenis, craig.topper, mgorny, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D44802

llvm-svn: 329139

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index c93207555c4..fe901fc2dd1 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -58,6 +58,7 @@ namespace llvm {
 
 void initializeWinEHStatePassPass(PassRegistry &);
 void initializeFixupLEAPassPass(PassRegistry &);
+void initializeShadowCallStackPass(PassRegistry &);
 void initializeX86CallFrameOptimizationPass(PassRegistry &);
 void initializeX86CmovConverterPassPass(PassRegistry &);
 void initializeX86ExecutionDomainFixPass(PassRegistry &);
@@ -77,6 +78,7 @@ extern "C" void LLVMInitializeX86Target() {
   initializeFixupBWInstPassPass(PR);
   initializeEvexToVexInstPassPass(PR);
   initializeFixupLEAPassPass(PR);
+  initializeShadowCallStackPass(PR);
   initializeX86CallFrameOptimizationPass(PR);
   initializeX86CmovConverterPassPass(PR);
   initializeX86ExecutionDomainFixPass(PR);
@@ -473,6 +475,7 @@ void X86PassConfig::addPreEmitPass() {
     addPass(createBreakFalseDeps());
   }
 
+  addPass(createShadowCallStackPass());
   addPass(createX86IndirectBranchTrackingPass());
 
   if (UseVZeroUpper)